If it&#146;s the same noise mine makes, it sound's like a quiet rod knock. Epically when you first start it. It&#146;s called Piston Slap. Get use to it if you own a 5.3. It&#146;s a design flaw that "supposedly" doesn't hurt the engine. Only time will tell. I have 77k on mine and it is still seems to be going strong. Except the front end is starting to make a lot of noise now.

The noise I am talking about only comes when I hit 65-70 mph and I think it has to do with the air deflector. It sounds like popping corn and it really isn't very loud. I saw that earlier discussions were about putting 2 sided tape somewhere but I am not sure where. Suspension and turning seem fine.... KNOCK ON WOOD!!!!!!!!!!!

chevy does not want you to know this (had to pry it out of a mechanic at the dealership) around 2000 or 2001 chevy changed the composition of metals in there rotors (big mistake) now every one i know that owns a new chevy has had the thing in for new rotors. They wanted to charge my grandfather 600 to replace the front rotors in his truck, (only 17,000mi on it) so i payed $150 for 2 aftermarket (not made by chevy) rotors and $20 for pads, swapped them out. its been over a year now and the rotors are just a as good as the day i put them on. good luck

I have had a recurring problem with my 2003 Avalanche. When the vehicle has been driven and is heated up I have a squeal while turning left only. Initially souned like a loose belt. Several power steering gears and a high pressure hose later the noise is reduced but is still there. Any info or suggestions on this issue are appreciated. Thanks

I have a 05 Av that has a rythmatic humming noise at 62 and 72. The truck has 410 gears(not sure if this is related). I brought it to another dealer after several attempts by the purchasing dealer. The transfer case is whats making the noise and there is a bullitin on it but no fix at this time. I have filed for arbitration under our state lemon law and it looks lokie a lost case for chevy. I also have a 2006 z-71 tahoe with 373's with no problems. Anyone who has this problem let me know if you have 410 gears.

I have put the velcro on the rubber pieces that cover the bolthead - to ne avail. HAving said that, next time you hear it on the highway, reach your hand up to the inside of the windshield where the windshiel and the frame meet. I will bet you feel the windshield ""fluttering" ever so slightly. I bet one or both or your outside mirrors probably shake as well. My Service Manager stated all this was normal. Then again, he just told be a bad front differential bearing ($900) and a bad rear differential bearing ($1200) failing at 57k miles is normal even thought I did the $30K check up ($650)

I get about the same mileage from an '06 crew cab Z71 4WD Silverado with the 5.3 engine and 3.73 gears. I seriously considered getting an Avalanche but poor visibility from the small rear window and smallish bed were the major decision factors. On the other hand I like the nice soft ride of the Avalanche. Silverado Z71 rides noticeably stiffer.

I have an '02 Chevy Avalanche w/ 45K miles, and lately I have been having problems with the 4 wheel drive. When turning corners, I hear a groaning noise and the vehicle begins to bind up and if I turn sharp enough, I can actually stop the vehicle as if I was braking. I've taken it into the dealer and they've told me it's normal. I've read in this forum others were having the same problem. Has anybody found a solution to this problem? Thanks for your help

If you're in 4Hi or 4Lo on a hard surface (or other surface with good traction for all 4 wheels) and experiencing this the dealer is right. If you're in A4WD on a hard surface then it probably should have disengaged 4wd on its own already and might need to be checked out. If you're in 2Hi and getting this then they definitely need to be checking the situation out.

Thanks for the feedback. You're right, 4 wheel drive is not intended to be used on dry hard surfaces. Where my concern came from is when I would compare my 4 wheel drive to other chevy truck/suv 4 wheel drive, and the other vehicles would not bind up or growl when turning like mine would. Could it be the hub assembly going bad?

I really don't know. My 2004 Z71 also growls a bit in 4WD, but nothing that worried me too much. From experience in other 1500's I consider it normal. When in 4WD they all seem a bit noisy. On the other hand it was almost impossible to tell the 2003 Trailblazer I replaced with it was in 4WD at all other than the obvious traction difference.

i also have a chevy avalanche with 410 gear/2004/4wd/z71/was told today there is something wrong in the transfer case. on 3 occasions i have had to take the truck to dealer as the 4x4 service light has come on,they said it was a faulty switch,needed to be re programed,it has had a growling noise from day one i was told the avalanche has alot of road noise thats probably the noise i am hearing ,the auto trac 4x4 also comes on by itself it will switch by itself from 2 wheel drive to auto trac,well now at 49000 miles after complaining several times about the 4x4 its got a problem with transfer case starting at a price range of 700.00 min. to tear down i am gonna fight this one not that i will get anywhere. also this truck has had the speedometer register 90 to 100 mph when you are actually going around 60 it will have a major problem for about three days then go back to normal has happened 3 times so far now that its out of warranty i was told they have had a problem with the cluster but not enough problem to warrant a recall the unit cost about 400 to 450 plus labor. a few other problems to bad they cant get it right the av could be a great truck its very universal.

28,000 mi front wheel bearing failed. replaced @ my own xpense. 32,000 transmission failed. dealer paid under warrantee. i now have 44,000 mi and trans has slipped once from stop. took back to dealer, i paid $44.00 for inspection they said ok. told them to remove pan. they said computer tells all, i really hope they are right, no xxtented warrantee !!! thank you mr. poppin ps. just replaced orig. tires with goodyear triple tread or "silent armor" tires, steering, (wierd noise on sharp turns have been eliminated)and ride is now xxcellant !!

Hello,I have a 2005 Avalanche. When I engage 4 wheel drive high, I get a loud noise from the front end. The noise isn't too bad when the wheels are straight, but when I turn the wheels (even just a bit) I hear a loud noise, almost like something rubbing against something else. I won't use the four wheel drive system until this is checked out because I don't want to damage anything.I called my dealer, gave him a verbal 'picture' of what was going on, and he said this noise was normal. I disagree. I have had other four wheel drive trucks and have never heard this noise before. I'm taking the truck to the dealer tomorrow to have it checked out. Has anybody else experienced this with their Avalanche? To better arm myself when I approach my dealer, I'd like to know if any of you have experienced this problem. If so, was there actually a problem which was diagnosed and repaired, or is this a noise I'm going to have to live with?Thanks! Any replies are much appreciated.Mark

I have an '02 Avalanche and have been experiencing the same thing. I also took it to the dealer and they told me it was normal. What I have found is when I engage the 4 wheel drive on a hard, dry surface, I hear the grinding noise. However, when I engage the four wheel drive in a muddy, snowy, or other slippery condition, the four wheel drive works great with little noise. I also experienced when I would turn sharp on a hard dry surface in four wheel drive, the wheels would actually bind up to the point where they would stop the vehicles progress forward. What was concluded from all this and from talking with others, the 4 wheel drive system is simply not intended to be engaged on dry hard surfaces. I think your "noise" is normal and you should be fine. I don't know if this offers much comfort, but it is what I have experienced with my Avalanche.

Hi Turibe,I certainly appreciate your reply. I took my truck to the dealer, and as expected...they said the noise was normal.When I get off work tonight I'll take a ride in some sand and see how it sounds.Once again, thanks for your reply.

I should have been more specific with my questions. What i was referring to are the "chips" or computer softwares you can install into your vehicle to change the factory settings for air/fuel ratio, timing aspects, and a few other things in order to either get more horsepower or better fuel economy. Most people use them for the diesel vehicles, but i've seen/heard of a few for gas engines.

Well all I can tell you is what I read from the "experts" and they all seem to say the same thing about chips...some work, some don't, and some work but aren't good for your truck.

So how to sort all this out? I think you need to shop carefully, first of all to determine the reputation of the chip vendor, then to ask them HOW they get the performance they claim (are they bumping the timing, or just extending the transmission shift points?) and also how much MPG you might LOSE (I'm a real skeptic about any device that claims to give you more power AND better mpg---that sounds rather contradictory to science).

Then if all this passes muster, I'd try to find someone who has already bought and TESTED the chip over time and get his/her testimonial.

My feeling is that factory engineers are very smart guys and that they don't leave lots of power on the table---and if they do leave a little HP on the table, it's a good idea to find out WHY they didn't add it to the stock vehicle. Most likely answers would be driveability in everyday use, and MPG.

Its possible to improve both power and economy with just a reprogrammed PCM. Search other truck forums for proof (dyno charts, etc. from end users and not just the people trying to sell you their chips).

Most people never see the actual posted hp and torque with their vehicles thanks to built in torque management. This retards engine timing with gear changes, gives soft shifts, and other similar tricks. The main reasons for this seem to be related to emissions, driver preference for "soft" shifting, and transmission life.

The 4L60E transmission in current GM trucks is long in the tooth, tracing back to the TH700R4, and wasn't originally designed to handle the power being made by the current crop of V8's. Part of the changes made to allow the bigger engines was softer shifts (reducing the amount of sudden torque load change) and engine retardation during shifts. This also reduces overall fuel efficiency and engine power output.

So, if you don't mind firmer shifts and aren't too "enthusiastic" with your driving you can benefit with a reprogram. You can also shorten your transmissions life if you enjoy yourself too much though.

BTW, GM isn't the only manufacturer doing this. Most of them have similar issues.